A Design and Development of the Learning Contents Management based on the Personalized Online Learning

Teaching-learning methods are undergoing rapid transformation in terms of new information and communication technology and in accordance with onset of the 4th Industrial Revolution. The educational environment is being transformed into various forms, with examples being found not only in the existing traditional educational environment, but also in online education and blended learning. Existing online learning (LMS, LCMS) is offered in a limited contents transmission online educational environment, and has been limited but the level of support offered to a learner’s personalized learning. This study will overview existing flexible model of contents, suggest possible problems, and attempt to solve these problems. LCMS was designed and realized based on the open source Moodle platform, offering personalized contents to learners. LCMS is composed of the following 3 functions: contents registration of metadata inputted by administrator; search functionality for personalized learner contents; and personalized contents automatically being recommended to learners. As a result of the research, we made online learning environment that can provide customized learning recommendation and self - directed learning by increasing the continuity and efficiency of learning by automatically providing customized online contents to learners. Through this study, the learning of students promises to be effectively initiated by being based on available LCMS functions related to personalized educational contents in online education

Innovation strategy of science and technology in Korea

노트 : 16th International Conference on Composite Material

Characterization of cationic dextrin prepared by ultra high pressure (UHP)-assisted cationization reaction

AbstractCationic dextrins were prepared through substitution reaction of dextrin with low and high addition levels of 2,3-epoxypropyltrimethylammonium chloride (ETMAC), respectively. Conventional cationization reactions were carried out for 5h under continued stirring. UHP-assisted cationization reactions were conducted at three pressurization levels of 100, 300 and 500MPa for a pressure holding time of 30min. Degree of substitution (DS) of UHP-assisted cationic dextrins ranged from 0.58 to 1.51, and in general, their DS values were enhanced with increasing pressure levels. FT-IR and 13C NMR spectra indicated the presence of CN bond, which provided clear evidence about incorporation of cationic moieties onto dextrin molecules. In flocculation test, UHP-assisted cationic dextrin revealed higher flocculating activity. Overall results suggested that UHP-assisted cationization reaction could modulate reactivity and flocculating activity of dextrin by controlling pressure levels and reaction mixture compositions, and cationic dextrins likely possessed a higher potential to replace synthetic polymer-based flocculants

Algae–bacteria interactions: Evolution, ecology and emerging applications

AbstractAlgae and bacteria have coexisted ever since the early stages of evolution. This coevolution has revolutionized life on earth in many aspects. Algae and bacteria together influence ecosystems as varied as deep seas to lichens and represent all conceivable modes of interactions — from mutualism to parasitism. Several studies have shown that algae and bacteria synergistically affect each other's physiology and metabolism, a classic case being algae–roseobacter interaction. These interactions are ubiquitous and define the primary productivity in most ecosystems. In recent years, algae have received much attention for industrial exploitation but their interaction with bacteria is often considered a contamination during commercialization. A few recent studies have shown that bacteria not only enhance algal growth but also help in flocculation, both essential processes in algal biotechnology. Hence, there is a need to understand these interactions from an evolutionary and ecological standpoint, and integrate this understanding for industrial use. Here we reflect on the diversity of such relationships and their associated mechanisms, as well as the habitats that they mutually influence. This review also outlines the role of these interactions in key evolutionary events such as endosymbiosis, besides their ecological role in biogeochemical cycles. Finally, we focus on extending such studies on algal–bacterial interactions to various environmental and bio-technological applications

Accelerating and Supersonic Density Fluctuations in Coronal Hole Plumes: Signature of Nascent Solar Winds

Slow magnetoacoustic waves in a static background provide a seismological tool to probe the solar atmosphere in the analytic frame. By analyzing the spatiotemporal variation of the electron number density of plume structure in coronal holes above the limb for a given temperature, we find that the density perturbations accelerate with supersonic speeds in the distance range from 1.02 to 1.23 solar radii. We interpret them as slow magnetoacoustic waves propagating at about the sound speed with accelerating subsonic flows. The average sonic height of the subsonic flows is calculated to be 1.27 solar radii. The mass flux of the subsonic flows is estimated to be 44.1$\%$ relative to the global solar wind. Hence, the subsonic flow is likely to be the nascent solar wind. In other words, the evolution of the nascent solar wind in plumes at the low corona is quantified for the first time from imaging observations. Based on the interpretation, propagating density perturbations present in plumes could be used as a seismological probe of the gradually accelerating solar wind.Comment: Accepted for publication in ApJL, 11 pages, 5 figure

Electrochemical Properties of Polyaniline-Coated Li-Rich Nickel Manganese Oxide and Role of Polyaniline Coating Layer

Polyaniline is coated on Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 synthesized via co-precipitation. X-ray diffraction patterns exhibit that the polyaniline coating does not affect structural change of the Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 , and the resulting transmission electron microscopic images show the presence of coating layers on the surface of Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 . Electrochemical tests using coin type cells confirm that the surface modification by polyaniline is effective in maintaining capacity and retention upon cycling. The conducting coating character also assists improvement in rate capability. The polyaniline layer forms F-doped polyaniline during cycling, as is proved by time-of-flight secondary ion mass spectroscopy. Therefore, the presence of the polyaniline layers plays a role in lowering HF levels via scavenging F − from HF in the electrolyte, and this F-doped polyaniline layer also assists in protecting the Li [Li 0.2 Efforts have been made to improve their intrinsic low rate capability stemming from the tetravalent Mn in the oxide matrix and cyclability as well. Hence, partial substitutions of Mn site with other elements or surface modifications have been made. 10,12 A recent report by Kang et al. 14 suggested that surface modification by Al(OH) 3 on Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 was fairly effective in capacity retention, rate capability, and thermal stability. Similar effects were also reported using Al 2 O 3 coating and AlPO 4 coating on the over-lithiated manganese oxides. 17,18 Furthermore, we perceive the main problem of oxide coating to be difficulty in complete encapsulation of active materials like core-shell materials due to condensation and crystal growth of the coating materials even at mild heat-treatment condition; it, hence, shows an islands-like coating. 18 For the reason, we object to complete encapsulation of Li[Li 0.2 Ni 0.2 Mn 0.6 ]O 2 using a conductive polyaniline, which does not need further heat-treatment after polymerization. Also, the conductive coating layers are expected to improve the rate capability of the active material. In this paper, we introduce the details of polyaniline-coated Li [ • C for 5 h. The dehydrates were thoroughly mixed with an appropriate amount of LiOH (samchun) and calcined at 900 • C for 15 h in air. In attempt to modify the as-synthesized active materials with polyaniline (hereafter referred as to be PANi), Cl − -doped emeraldine salt state PANi ([C 24 H 26 N 4 (Cl) 2 ] n ) was polymerized with aniline monomer (C 6 H 5 NH 2 ) and ammonium persulfate ((NH 4 ) 2 S 2 O 8 ,). First, aniline monomer and ammonium persulfate were separately poured into 1M HCl aqueous solution, and they were mixed to self-polymerize for 2 days. And the produced PANi in the solution was rinsed with absolute ethanol and acetone to remove the residual monomer, oligomer, and low molecular weight organic intermediates. To prepare violet pernigraniline base state (hereafter referred as to be VPB) PANi which needs to be dissolved in N-methyl-2-pyrrolinon(NMP) or m-cresol and so on, 19,20 the Cl − -doped PANi was poured into a 1M NaOH aqueous solution and continuously stirred at 350 rpm for 2 days. Then, the solution was dried at 80 • C in air. The obtained VPB powders were mixed with campor-10-sulfonic acid, β (CSA, Sigma-aldrich, with a ratio of 4:1 in weight) to prepare (SO) 3 2− -doped emeraldine salt state (hereafter referred as to be ES) PANi and dissolved into N-methyl-2-pyrrolinon (NMP X-ray diffractometry (XRD, Rint-2000, Rigaku) and highresolution transmission electron microscopy (HR-TEM, JEM-3010, JEOL) were employed to characterize the synthesized powders. Timeof-flight secondary ion mass spectroscopy (ToF-SIMS, PHI TRIFT V nanoTOF, ULVAC-PHI) was also used to confirm the presence of th